It should be a rule to ping the original poster when crossposting.
The point of this subreddit is to lightly mock overly pretentious photographers when their skills do not actually tally, not to harbour cold-blooded hate towards practitioners of their own hobby in their corner.
It's better to lightly banter and invite the OP to this sub after their photo is posted so everybody can have a laugh if possible, and not the OP discovering everybody has been mocking them behind their backs, which can cause distress.
Many jerkers believe their work is actually the real thing and they should get a chance to interact to their mockery. Who knows they learn a thing or two about photography.